Integration of electronic data storage into a telecommunications component

ABSTRACT

A storage information system is disclosed for keeping archival information on the individual active optoelectronic components that are used in telecommunication equipment. The system involves enclosing a nonvolatile memory chip inside the hermetic package of the active optoelectronic component. A memory chip is used to keep the relevant information about the active optoelectronic component such as serial number, part number and specifications. Sensors can also be included inside the hermetic package to monitor the operating conditions of the optoelectronic component. The information system is capable of storing information that is relevant to the component reliability such as: hours of operation, maximum current or voltage, and maximum temperature. The information storage system has the advantage that the archived information is intimately associated with the optoelectronic component thereby lessening the likelihood that information is lost or tampered with. The information system eliminates need for keeping paper records on individual optoelectronic components. It also provides a means for determining if the optoelectronic component was operated outside its specified operating limits. The users of optoelectronic components can also access the information system as needed for the purposes of repair or maintenance of telecommunications equipment.

RELATED APPLICATIONS PRIORITY DATA

[0001] This application claims the benefit of U.S. Provisional PatentApplication No. 60/384,165, filed May 31, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates to optoelectronic components andmore particularly to storing records of information on or withinindividual components.

BACKGROUND OF THE INVENTION

[0003] Telecommunication equipment uses a variety of differentcomponents. Keeping track of these individual components through thevarious stages of assembly and test of the equipment is a time-consumingand expensive process. Furthermore, after delivery of the equipment tothe customer, there is often a need to provide information on or withthe components to the customer. Component information is also needed inthe repair and maintenance of the equipment in the telecommunicationsnetwork. The provision, handling and storage of such componentinformation is time consuming and costly both to the telecommunicationsequipment manufacturer and the customer.

[0004] The component information is usually provided in paper orelectronic form and is linked to the component by means of a serialnumber marked on the component or on its container.

[0005] The problems associated with keeping track of individualtelecommunication components are exacerbated in the case of activeoptoelectronic components, which are devices that are used for thegeneration, detection, and/or modulation of light. For example, activeoptoelectronic components that are used in terrestrial and/or underseafiber optic communication are required to have high-reliability levelsor low-failure rates; a typical failure rate can be less than 1000 per10⁹ device hours of operation. To insure such low-failure rates requiresstringent control over the conditions under which the device wasmanufactured as well as control over the operating conditions that thedevice experiences. Thus the assurance of the reliability performance ofoptoelectronic components places a unique requirement on the componentinformation needed. For example, there may be a need to have records ofthe operating conditions of a component during its functional lifetime.

[0006] When being used, typical active optoelectronic devices arerestricted to operate within the bounds of a predetermined set ofoperational parameters. The bounds for this set of operationalparameters are usually expressed as an absolute maximum and/orminimum—temperature, current, voltage etc. or any combination of theseor other parameters. Thus there is an envelope of operational parameterswithin which the optoelectronic device can be safely used. Operation ofthe optoelectronic device outside the bounds of the envelope can resultin catastrophic failure or it can have a harmful effect on the long-termreliability of the device. That is, operating the device outside theenvelope of operational parameters, may lead to degradation in device,which is not apparent on return to the normal operating conditions ofthe device. Nevertheless, the life-time or reliability of the device maybe shortened or decreased. Thus it is advantageous to keep a record ofthe operating conditions of the optoelectronic device for the purposesof identifying potentially lower reliability devices and as a means forguaranteeing the device reliability. It is also advantageous in the caseof device warranties to have a record of the operating conditions inorder know whether the device was used properly within its operationalparameter limits. Therefore it is desired that the security of therecorded information be ensured.

[0007] Since the adverse operating conditions can occur even during themanufacture of the optoelectronic component, it is desirable to initiatethe recording of the operating conditions as soon as possible in themanufacturing process. Currently, such information is recorded andstored on paper or in computer memory as for example the database of amanufacturing execution system. However, due to the complexities of themanufacturing processes and its supporting data systems, it may not bepractical to keep such a record of the operating parameters. This isparticularly true if the optoelectronic part is small which precludessimple methods for marking the part with an identification mark.

[0008] When the optoelectronic component is shipped to the customer forinstallation into a larger assembly, additional problems occur. Firstlythere is no assurance that the component operational conditions will berecorded and stored by the customer. Often, the customer will ship theassembly containing the component to third party thereby making thekeeping of a record of operational conditions of the component even moredifficult. It is known that the customer will often resist requirementsplaced on them to maintain such records because of extra costs andinconvenience incurred. The primary benefit of such records is for themanufacturer who wishes to provide guarantees of reliability for theirdevices. Thus manufacturers would prefer a means for recording therelevant operational information and a means for storing thisinformation that is completely transparent to the customer. That is, norequirements are placed on the customer to collect and keep informationon the operational conditions of the optoelectronic device.

[0009] It is an object of this invention to provide a means forrecording and storing optoelectronic component information and theoperating conditions and parameters of an optoelectronic component thatare relevant to component reliability.

[0010] It is a further object of this invention that the means forrecording and storing the information is secure, is accessible to beread by the customer, and does not place an extra burden on the customerto monitor the optoelectronic operating conditions and to store thecollected information.

SUMMARY OF INVENTION

[0011] In accordance with the invention a system for the archivalstorage of information about an active optoelectronic component isprovided that overcomes the current problems associated with keepingtrack of individual components in telecommunication equipment. Thestorage system of the present invention is capable of keeping recordsabout the individual optoelectronic component including such informationas serial number, part number, model type, specifications, operatinginformation, and individual component performance data. The presentinvention is particularly applicable to active optoelectronic componentssuch as laser diodes, optical modulators, optical amplifiers, andphotodetectors.

[0012] In accordance with the invention, the information storage systemis also provided with a means for recording the operating conditions ofan optoelectronic component during its functional lifetime therebyeliminating the need for the user of the optoelectronic component tocreate and keep such records. Thus the information storage system of thepresent invention is capable of keeping records on the operatingconditions of individual active optoelectronic components, which mayinclude such information as hours of operation, maximum current, maximumvoltage, maximum temperature.

[0013] In accordance with a preferred embodiment of the invention, theinformation storage system is an optoelectronic device that contains anonvolatile memory chip inside the same hermetic package that enclosesthe active optoelectronic component. Thus in the present invention, themeans used for storage of the component information is closelyassociated physically with the active optoelectronic component in thesame hermetic package thereby ensuring the security of the informationsince the information is stored with the component and cannot beaccessed physically except by breaking the hermetic seal.

[0014] In accordance with another embodiment of the invention, theinformation storage system uses sensors for monitoring the operating andenvironmental conditions of the active optoelectronic component and thesensors are located inside the same hermetic package of theoptoelectronic device that contains the memory chip and the activeoptoelectronic component. Thus in the present invention, the sensors areclosely associated physically with the optoelectronic component therebyensuring that the environmental conditions that are being monitored aresimilar to those being experienced by the active optoelectroniccomponent. This means for monitoring the operating and environmentalconditions of the active optoelectronic component in the presentinvention has the additional benefit that the user of the component doesnot need to be concerned about performing these functions when using theactive optoelectronic component.

[0015] In accordance with the invention, the information storage systemprovides a means inside the hermetic package for receiving informationabout the operating and/or environmental conditions experienced by theactive optoelectronic component and storing this information in thenonvolatile memory chip. The present invention also provides means foraccessing the memory chip inside the package from outside the packagefor the purpose entering component information data such as serialnumber, part number, component specifications and performance data andstoring it permanently in the nonvolatile memory chip. In addition, thisaccess means of this present invention permits reading the informationcontents of the memory chip from outside the hermetic package thusenabling a user of component to have ready access to the informationneeded in the maintenance and repair of telecommunication equipment. Thepreferred method of access is electrical by means of conductingfeed-throughs into the hermetic package. In order to improve thesecurity of the information contained on the chip, the present inventionmay use encryption techniques for the transfer of data to and from thememory storage means inside the hermetic package.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be described in greater detail with referenceto the accompanying drawings, which represent preferred embodimentsthereof, wherein:

[0017]FIG. 1 is a schematic diagram showing the integration of a memorychip on a submount platform of a laser pump module.

[0018]FIG. 2 is a schematic diagram showing the placement of thesubmount platform in a hermetically sealed butterfly package.

[0019]FIG. 3 is another embodiment of the invention with the memory chipbonded to the chip as the laser diode.

DETAILED DESCRIPTION

[0020] To obtain a record of the operating conditions of anoptoelectronic device in a hermetic package during its functionallifetime, the relevant operating parameters need to be monitored andrecorded. The most straightforward approach would be to monitor therelevant operating parameters external to the hermetic package and tostore them electronically in a memory chip in the optical subsystem thatcontains the optoelectronic component. There is considerable prior artteaching the use of a memory chip on a PCB associated with a laser diodefor the purpose of recording similar type information on the laserdiode.

[0021] U.S. Pat. No. 5,278,404 in the name of Yeates discloses anoptical sub-system with an embedded micro-controller that has memorystorage. The memory in the micro-controller is used to store the optimumoperating parameters of the optoelectronic component under differentenvironmental conditions. Thus the micro-controller has a means foroptimizing the operation of the optoelectronic device to differentenvironmental conditions. Although the memory in this micro-controlleris used for a different purpose, it could also be used to record andstore the operating parameters of the optoelectronic component duringits functional lifetime. Such a solution to problem of recording andstoring the required information on an optoelectronic component isunsatisfactory in that the security of the information is not ensuredand it requires the involvement of the customer.

[0022] To overcome these problems, it is proposed to include anonvolatile memory chip within the hermetic package of theoptoelectronic component. This memory would be used for storingmanufacturing data, product data, and the recording of the operationaland performance history of the optoelectronic component during itsfunctional lifetime. Sensors may also be included in the package toprovide a record of the environmental conditions experienced by thelaser diode. Although this invention increases the complexity of thelaser diode hermetic package, there are many benefits that are obtainedby including the memory inside the hermetic package rather then outsidethe hermetic package.

[0023] In the case of electronic memory that is external to the hermeticpackage, the designer and manufacturer of the subsystem that includesthe hermetically sealed optoelectronic package needs to incorporate inthe design of the subsystem monitoring, electronic circuitry andelectronic memory to record and store the required information. It ispreferable, however, that the customer does not have to be concernedwith this aspect of the operation of the optoelectronic component.Furthermore the security of the component information is not ensuredwhen the memory is external to the hermetic package. Although the memorychip is associated with the optoelectronic component in that they are inthe same subsystem, they are still separate components. The memory chipcould be removed from the system and be replaced with another with noapparent evidence that such an exchange was made. However, with thememory chip inside the hermetic package, this security problem iseliminated.

[0024] Another problem with performing the recording and monitoringfunction external to the optoelectronic hermetic package is that someparameters, such as temperature, the value measured depends on whetherthe sensor is inside the package or outside the package. A sensor insidethe hermetic package will measure a temperature different from oneoutside the package. What is relevant as far as device reliability isconcerned, is the temperature inside the package. Thus it is desirableto place the sensors as close as possible to the optoelectroniccomponent being monitored. Furthermore, for some parameters, the sensormust be inside the package so that it is in the same atmosphericconditions being experienced by the optoelectronic component. Thereliability of an optoelectronic device can be affected by the presenceof certain gases or organics in the atmosphere surrounding thecomponent. The detection of these materials requires the sensor to beplaced inside the same package as the optoelectronic component.

[0025] Finally, a memory chip that is inside hermetic package isassociated physically with the optoelectronic component thereby ensuringthe security of the recorded information. That is the memory cannot beremoved from the package without damaging the hermetic seal. Thecontents of the memory however, are still available for access by thecustomer when needed, but otherwise the customer does not have to beconcerned with the collecting of the information to be stored in thememory.

[0026] The invention is now illustrated more fully in terms of a pumplaser diode being the optoelectronic component of interest.

[0027]FIG. 1 and FIG. 2 show an embodiment of the invention in which asensor/memory chip 10 is provided with a pump laser diode 11 in ahermetic butterfly package 12. The sensor/memory chip is mounted on thesame platform 13 as the pump laser, so as to experience as nearly aspossible, the same temperature and atmospheric conditions as the laserchip. The sensor/memory chip is a silicon ASIC containing sensingelectronics for current and temperature. The temperature sensing may bea thermistor integrated with the sensor/memory chip or it may be aseparate chip within the package. The sensor/memory chip also contains acurrent sensor connected in series with the laser diode to measure thelaser current and an analog-to-digital converter to convert themeasurements of temperature and/or current into digital form.

[0028] The memory chip 10 can be a data chip that is commerciallyavailable. The invention, however, is not limited to a particular typeof electronic memory. The memory should be nonvolatile so the records ofextremes of temperature and current under operational conditions arestored permanently. It may also be desirable to store the data inencrypted form. There is an additional requirement that the memory chiphave a serial electronic interface to permit interrogation and/or meansfor altering the contents of the memory. Although the preferred methodof storing and communicating with the storage means is electrical, it isapparent that other storage and communications means such as optical arewith in the scope of the present invention. The key considerations withrespect to the memory means are the memory chip size and the number ofpins required for communication. It is preferable the chip be physicallysmall so that it can fit in the hermetic package. The connection betweenthe sensor/memory chip and the outside world is made through one of thepins of the hermetic package that is not normally used. The preferredconfiguration for communications to the outside is one data pin and oneground pin.

[0029]FIG. 3 shows another embodiment of the invention. In this case thememory chip 10 is integrated with laser diode on the same substrate. Thefunctions of the memory chip are similar to that in the firstembodiment. The advantage of this embodiment is that a smaller hermeticpackage is possible.

[0030] The invention has been described in terms of a pump laser diode,but it should be apparent to one skilled in the art that the inventionalso applies to other active optoelectronic components such assemiconductor optical amplifiers, optical modulators, andphotodetectors.

[0031] The types of data information that are stored in the memory canalso be very diverse. For example, depending on the specific type ofoptoelectronic device, storage of information related to: currentsupplied to device, voltages applied to device, temperature experiencedby the device, optical intensity incident on and/or emitted by thedevice, elapsed hours of operation, manufacturing part codes, productcodes, etc. are all considered with in the scope of the invention.

[0032] The invention has also been described in terms of a hermeticallysealed package, which in the normal sense has the meaning of a package,which is airtight. That is air or moisture on the outside of the packagecannot penetrate into the package. There are other forms of packaging,which are considered non-hermetic but would still lie with in the scopeof the invention. An example of such packaging is an optoelectroniccomponent and a memory chip encased with in a molded plastic package. Interms of the invention, a hermetic package is deemed to include anypackage in which the memory chip and the optoelectronic are enclosedtogether in a package and sealed in such a manner that separation of thememory chip from the optoelectronic component results in physical damageto the package or the seal.

What is claimed is:
 1. An optoelectronic device, comprising: an activeoptoelectronic component a package enclosing the active optoelectroniccomponent a nonvolatile memory inside the package for keeping componentinformation and operating conditions information on the activeoptoelectronic component, electronic circuitry connecting thenonvolatile memory and the active optoelectronic component fortransferring the information on the operating conditions of the activeoptoelectronic component to the nonvolatile memory; and at least oneconnection through the package linking the nonvolatile memory to theoutside of the package in order to provide means for reading or writingthe component information into or out of the nonvolatile memory: whereinthe package is substantially hermetically sealed.
 2. An optoelectronicdevice as defined in claim 1 further comprising: at least one sensorinside the package for monitoring the environmental conditions relatedto the active optoelectronic component and, electronic circuitry insidethe package for connecting the sensor to the nonvolatile memory in orderto transfer information on the environmental conditions of the activeoptoelectronic component to the nonvolatile memory.
 3. An optoelectronicdevice as defined as in claim 1 wherein the connection through thepackage is at least one electrical conducting hermetic feed-through. 4.An optoelectronic device as defined in claim 1, wherein the activeoptoelectronic component is at least one of: a laser diode, an opticalamplifier, an optical modulator, and an optical detector.
 5. Anoptoelectronic device as defined in claim 1, wherein the operatingconditions information is at least one of: current, voltage opticalpower, and hours of operation.
 6. An optoelectronic device as defined inclaim 1, wherein the component information is at least one of: serialnumber, part number, model number, active optoelectronic componentspecifications, and active optoelectronic component performance data. 7.An optoelectronic package as defined in claim 2 wherein theenvironmental conditions information is at least one of: temperature,pressure, shock, water, and ingredients of the atmosphere inside thepackage.
 8. An information storage system for keeping componentinformation and operating conditions information on an activeoptoelectronic component comprising of: a sealed package; an activeoptoelectronic component inside the sealed package; a nonvolatile memorychip inside the sealed package; electronic circuitry inside the sealedpackage connecting the nonvolatile memory to the active optoelectroniccomponent in order to transfer the information on the operatingconditions of the active optoelectronic component into the nonvolatilememory; and, at least one connection through the sealed package linkingthe nonvolatile memory to the outside of the sealed package to transferinformation into or out of the nonvolatile memory.
 9. An informationstorage system as defined in claim 8 further comprising: at least onesensor inside the sealed package for monitoring the environmentalconditions of the active optoelectronic component and, electroniccircuitry inside the sealed package connecting the sensor to thenonvolatile memory in order to transfer information on the environmentalconditions of the active optoelectronic component to the nonvolatilememory.
 10. An information storage system as defined in claim 8 whereinthe connection through the sealed package is one of electrical andoptical.
 11. An information storage system as defined in claim 8 whereinthe component information for the active optoelectronic component is atleast one of: serial number, part number, model number, activeoptoelectronic component specifications, and active optoelectroniccomponent performance data.
 12. An information storage system as definedin claim 8 wherein the operating conditions information for the activeoptoelectronic component is at least one of: hours of operation,current, voltage, and light intensity.
 13. An information storage systemas defined in claim 9 wherein the environmental information on theactive optoelectronic components is at least one of: temperature,pressure, shock, and moisture.